file_cache_statistics
Overview
Used to view the metric information related to data cache on each BE node. The metric information is sourced from the monitoring metrics related to BE's data cache.
This system table is supported from versions 2.1.6 and 3.0.2.
Belongs to Database
information_schema
Table Information
Column Name | Type | Description |
---|---|---|
BE_ID | BIGINT | BE node ID |
BE_IP | VARCHAR(256) | BE node IP |
CACHE_PATH | VARCHAR(256) | BE node cache path |
METRIC_NAME | VARCHAR(256) | Metric name |
METRIC_VALUE | DOUBLE | Metric value |
Different Doris version may have different metrics
2.1.x Metrics
Only important metrics are listed.
normal_queue_curr_elements
Number of File Blocks currently in the cache.
normal_queue_max_elements
Maximum number of File Blocks allowed in the cache.
normal_queue_curr_size
Current cache size.
normal_queue_max_size
Maximum cache size allowed.
hits_ratio
Overall cache hit ratio since BE startup.
hits_ratio_5m
Cache hit ratio in the last 5 minutes.
hits_ratio_1h
Cache hit ratio in the last 1 hour.
3.0.x Metrics
TODO
Examples
Query all cache metrics
mysql> select * from information_schema.file_cache_statistics;
+-------+---------------+----------------------------+----------------------------+--------------------+
| BE_ID | BE_IP | CACHE_PATH | METRIC_NAME | METRIC_VALUE |
+-------+---------------+----------------------------+----------------------------+--------------------+
| 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | normal_queue_curr_elements | 1392 |
| 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | normal_queue_curr_size | 248922234 |
| 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | normal_queue_max_elements | 102400 |
| 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | normal_queue_max_size | 21474836480 |
| 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | hits_ratio | 0.8539634687001242 |
| 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | hits_ratio_1h | 0 |
| 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | hits_ratio_5m | 0 |
+-------+---------------+----------------------------+----------------------------+--------------------+Query cache hit ratio and sort by hit ratio
select * from information_schema.file_cache_statistics where METRIC_NAME = "hits_ratio" order by METRIC_VALUE desc;